A series of storm systems will bring a continued threat for heavy rain, strong winds, and rough surf to coastal locations from northern California to the Northwest U.S. into the weekend. Heavy snow will be likely across the Intermountain West. Over the Eastern U.S., low pressure will gather strength and move up the eastern seaboard through Saturday bringing ice, rain, and gusty winds. Read More >
The WetBulb Globe Temperature (WBGT) is a measure of the heat stress in direct sunlight, which takes into account: temperature, humidity, wind speed, sun angle and cloud cover (solar radiation). This differs from the heat index, which takes into consideration temperature and humidity and is calculated for shady areas. If you work or exercise in direct sunlight, this is a good element to monitor. Military agencies, OSHA and many nations use the WBGT as a guide to managing workload in direct sunlight.
|
|
![]() |
![]() |
WetBulb Globe Temperature | Heat Index |
Comparison with Heat Index
|
Examples
|
Preparedness - What to do before doing outdoor activities when the WBGT is high -
|
Other Resources
|
More WBGT Information WBGT Research Paper OSHA work load and WBGT Manual |
Suggested Actions and Impact Prevention | ||
WBGT(F)
|
Effects
|
Precautionary Actions
|
< 80 | ||
80-85 | Working or exercising in direct sunlight will stress your body after 45 minutes. | Take at least 15 minutes of breaks each hour if working or exercising in direct sunlight |
85-88 | Working or exercising in direct sunlight will stress your body after 30 minutes. | Take at least 30 minutes of breaks each hour if working or exercising in direct sunlight |
88-90 | Working or exercising in direct sunlight will stress your body after 20 minutes. | Take at least 40 minutes of breaks each hour if working or exercising in direct sunlight |
>90 | Working or exercising in direct sunlight will stress your body after 15 minutes. | Take at least 45 minutes of breaks each hour if working or exercising in direct sunlight |